Multimode stimuli responsive dual-state organic room temperature phosphorescence from a phenanthrene derivative

Organic stimulus-responsive phosphorescence has aroused widespread interest due to their potential applications in the next generation of intelligent materials. Herein, multimode stimulus responsive dual-state room temperature phosphorescence (RTP) is developed for the first time from a phenanthrene derivative (BrPCN). BrPCN crystal cultured in DMF solvent exhibits red RTP at 615 nm. The red RTP can be excited by visible light at 502 nm, and turned into a green fluorescence at 559 nm upon vacuuming (or heating, grinding), and recovered by DMF fuming. The repeatable switching between the red RTP and green fluorescence in aggregated state is achieved by inhaling/removing DMF. It has been proved that a tiny amounts of guest molecule (named as NPCN), was produced in the recrystallization process of BrPCN host. The host–guest cluster formed from BrPCN and NPCN become the emissive central for red RTP activated by DMF. Interestingly, the orange-red single molecular RTP (at 580 nm) of BrPCN can be turned on in a polymer by photoactivation with a quantum yield of 13.9%. On the base of the dual-state RTP of BrPCN sensitive to external stimuli, a determinant-based sophisticated password lock and an anti-leakage information encryption system are explored. These results provide a new way for the design and application of multimode phosphorescent stimulus-responsive materials.